Comb plate for sheep-shearing-machine handpieces



W. G. MAW

Aug. 20, 1929.-

COMB PLATE FOR SHEEP SHEARING MACHINE HANDPIECES Filed April 3, 1928 Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

WILFRED GIBSON MAW, OF DURSLEY, ENGLAND, ASSIGNOR TO B. A. LISTER & COM- PANY LIMITED, OF DURSLEY, ENGLAND, A BRITISH COMPANY.

COMB PLATE FOR SHEEP-SHEARING-MACHINE HANDPIECES.

Application filed April 3, 1928, Serial No. 266,924, and in Australia June 20, 1927.

This invention relates to combs or combplates for sheep-shearing machine handpieces, and a method of manufacturing the same.

Heretofore combs or comb-plates for sheepshearing machine hand-pieces have been machined out of a blank which was usually of uniform thickness throughout. It has, however, been proposed that such combs may be produced from blanks of tapering section, or may be built up of a permanent underpart forming a carrier and having teeth points, and an insert-plate occuping the path covered by the cutter-plate in its movement across the comb, and adapted to be removed and resharpened. In all these cases the manufacture of the comb is a costly process. In view of the very large number of combs used in the sheep-shearing industry, simplification of construction and reduction in cost of manufacture have become important considerations in the trade.

This invention has for its main object to attain these ends and to provide an improved comb or comb-plate which can be produced at a minimum cost without depreciation in efiiciency. A further object is to provide an improved method of manufacturing such combs or comb-plates.

According to an important feature of the invention, there is provided a sheep-shearing machine comb or comb-plate formed by stamping and subsequent machine finishing from a blank that has a thicker marginal portion which is adapted to provide solid bodied teeth and is connected by a portion of rapidly decreasing thickness with a thinner portion constituting the body of the comb.

According to another feature of the invention, the body of the comb is shaped by stamping in the form of a pan having flanges at its lateral edges and at the edges of slots in the body, and also having areas upset and finished level with the comb face of said flanges to provide a bearing support for the rear edge of a cutter.

The invention further provides a sheepshearing machine comb or comb-plate whereof the palm portion is formed pan-like by stamping, with integral solid teeth and upset bearing areas for co-operating with a cutter.

Further, a method of manufacturing a according to the invention comprises the steps of making a comb-blank of two thicknesses having a thinner bodyeportion connected by a portion of rapidly increasing thickness with a thicker marginal portion for the teeth, and shaping the body-portion by stamping to form the palm of the comb.

Two embodiments of the invention are diagrammatically illustrated by way of example in the accompanying drawing, where- 1n:

Figure 1 is a cross-section of a stri of steel rolled to two different thicknesses rom which strip blanks for the combs are cut;

Figure 2 is a side elevation of a blank,

wherein teeth have been blanked out in the thicker portion and slots have been cut in the thinner portion;

Figure 3 is a top plan view of one form of finished comb according to the invention;

Figure 4 is a side elevation thereof.

Figure 5 is a section taken on the line 55 in Figure 3; and

Figures 6 and 7 are side elevation, and top plan view, respectively, of a modified form of finished comb according to the invention.

As shown in Figure 1, a strip of steel is rolled with a thicker marginal portion A for a width equal to about one-third of the total width of the strip, and a substantially rectangular blank is cut from it. In this thicker portion A of the blank the tooth bodies are blanked out, slots for holding screws are cut in the thinner portion D and subsequently flanges and bearing areas for the cutter are formed by stamping in the thinner body portion D, as.described hereinafter.

The thick portion A of the blank provides the solid material for tooth bodies B, the solid portion extending back from the teeth points for about two-thirds or more of the total length of each tooth. The rootportion C of each tooth is level with the face-portion B, the stamping providing an upstanding edge continuous with the floor B. Flanges E are provided at the lateral edges of the thinner body-portion D of the blank and impart to the finished comb or comb-plate longitudinal rigidity, and this rigidity is also assisted by the up-stamping of the marginal portions F of holding screw slots G at the rear end of the plate opposite the teeth, Further stiffening of the comb body is obtained by the up-stamping of two landing areas H which also are at floor level with the tooth faces B, which areas serve to support the back edge of the cutter plate when the comb is in use. One position of the cutter plate when at work is indicated in broken lines in Figure 8.

The two landing areas H support the heel portion of the cutter, while the tooth portion of the cutter rides over the teeth of the comb in the usual way and has a good surface bearing on the broad portions of the teeth. Satisfactory rigidity of the comb body and secure attachment to the machine L body is obtained with combs constructed in this manner, and a sufiicient bearing for the cutter is obtained, so that true and smooth running of the cutter over'the comb is attained.

The invention thus provides a method of manufacturing combs or comb-plates of the kind described comprising the steps of making a comb-blank of two thicknesses having a thinner body-portion D connected by a portion of rapidly increasing thickness with a thicker marginal portion A for the teeth, for example from a strip of steel of the cross-section shown in Figure 1, blanking out or milling the teeth in the thicker portion A, shaping the thinner portion in the form of a pan by one or more stamping operations and thereby providing it with lateral flanges and with upset bearingareas for co-operating with a cutter, and disc grinding the cutter face of the comb. The stem portions of the teeth are preferably slightly undercut to give a sled-like form to the bottom edges of the leading ends of the teeth, the teeth faces and points being shaped up and finished by grinding according to usual workshop practice. Owing to the bottom edges of the front parts of the teeth underlying the path of the cutter points being made sled-like in shape a freer riding bearing of the comb is obtained than would be the case if the back edges of the comb teeth were quite straight. This sledding of the front ends of the teeth is, however, a minor feature of the invention, the important feature being the production of combs by stamping and subsequent machine finishing from a blank of two diiferent thicknesses of material.

As shown in Figures 6 and 7, the side flanges E may be notched out as shown at K, in accordance with usual practice, to permit liberation of dust and wool which may be entrained under the cutter, but such are not essential in. this stamped-out type of comb. The shape, area and disposition of the two landing areas H is subject to modification. Also, a holeM may be formed through each of these areas, as illustrated, to allow of liberation of dust and the like, in which case the notches K, however, need not be provided. These and other modifications may be made in the details of construction described abovewithout departing from the invention as defined in the claim.'

I claim:

A sheep-shearing machine comb comprising a plate having a thick marginal forward portion that is shaped to provide solidbodied teeth and is connected by aportion of rapidly decreasing thickness with a thinner rearward portion constituting the body of the comb.

In testimony whereof I affix my signa-' ture.

WILFRED GIBSON MAW. 

